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1 
2 /* Parser generator main program */
3 
4 /* This expects a filename containing the grammar as argv[1] (UNIX)
5    or asks the console for such a file name (THINK C).
6    It writes its output on two files in the current directory:
7    - "graminit.c" gets the grammar as a bunch of initialized data
8    - "graminit.h" gets the grammar's non-terminals as #defines.
9    Error messages and status info during the generation process are
10    written to stdout, or sometimes to stderr. */
11 
12 /* XXX TO DO:
13    - check for duplicate definitions of names (instead of fatal err)
14 */
15 
16 #include "Python.h"
17 #include "pgenheaders.h"
18 #include "grammar.h"
19 #include "node.h"
20 #include "parsetok.h"
21 #include "pgen.h"
22 
23 int Py_DebugFlag;
24 int Py_VerboseFlag;
25 int Py_IgnoreEnvironmentFlag;
26 
27 /* Forward */
28 grammar *getgrammar(char *filename);
29 
30 void
Py_Exit(int sts)31 Py_Exit(int sts)
32 {
33     exit(sts);
34 }
35 
36 int
main(int argc,char ** argv)37 main(int argc, char **argv)
38 {
39     grammar *g;
40     FILE *fp;
41     char *filename, *graminit_h, *graminit_c;
42 
43     if (argc != 4) {
44         fprintf(stderr,
45             "usage: %s grammar graminit.h graminit.c\n", argv[0]);
46         Py_Exit(2);
47     }
48     filename = argv[1];
49     graminit_h = argv[2];
50     graminit_c = argv[3];
51     g = getgrammar(filename);
52     fp = fopen(graminit_c, "w");
53     if (fp == NULL) {
54         perror(graminit_c);
55         Py_Exit(1);
56     }
57     if (Py_DebugFlag)
58         printf("Writing %s ...\n", graminit_c);
59     printgrammar(g, fp);
60     fclose(fp);
61     fp = fopen(graminit_h, "w");
62     if (fp == NULL) {
63         perror(graminit_h);
64         Py_Exit(1);
65     }
66     if (Py_DebugFlag)
67         printf("Writing %s ...\n", graminit_h);
68     printnonterminals(g, fp);
69     fclose(fp);
70     Py_Exit(0);
71     return 0; /* Make gcc -Wall happy */
72 }
73 
74 grammar *
getgrammar(char * filename)75 getgrammar(char *filename)
76 {
77     FILE *fp;
78     node *n;
79     grammar *g0, *g;
80     perrdetail err;
81 
82     fp = fopen(filename, "r");
83     if (fp == NULL) {
84         perror(filename);
85         Py_Exit(1);
86     }
87     g0 = meta_grammar();
88     n = PyParser_ParseFile(fp, filename, g0, g0->g_start,
89                   (char *)NULL, (char *)NULL, &err);
90     fclose(fp);
91     if (n == NULL) {
92         fprintf(stderr, "Parsing error %d, line %d.\n",
93             err.error, err.lineno);
94         if (err.text != NULL) {
95             size_t i;
96             fprintf(stderr, "%s", err.text);
97             i = strlen(err.text);
98             if (i == 0 || err.text[i-1] != '\n')
99                 fprintf(stderr, "\n");
100             for (i = 0; i < err.offset; i++) {
101                 if (err.text[i] == '\t')
102                     putc('\t', stderr);
103                 else
104                     putc(' ', stderr);
105             }
106             fprintf(stderr, "^\n");
107             PyObject_FREE(err.text);
108         }
109         Py_Exit(1);
110     }
111     g = pgen(n);
112     if (g == NULL) {
113         printf("Bad grammar.\n");
114         Py_Exit(1);
115     }
116     return g;
117 }
118 
119 /* Can't happen in pgen */
120 PyObject*
PyErr_Occurred()121 PyErr_Occurred()
122 {
123     return 0;
124 }
125 
126 void
Py_FatalError(const char * msg)127 Py_FatalError(const char *msg)
128 {
129     fprintf(stderr, "pgen: FATAL ERROR: %s\n", msg);
130     Py_Exit(1);
131 }
132 
133 /* No-nonsense my_readline() for tokenizer.c */
134 
135 char *
PyOS_Readline(FILE * sys_stdin,FILE * sys_stdout,char * prompt)136 PyOS_Readline(FILE *sys_stdin, FILE *sys_stdout, char *prompt)
137 {
138     size_t n = 1000;
139     char *p = (char *)PyMem_MALLOC(n);
140     char *q;
141     if (p == NULL)
142         return NULL;
143     fprintf(stderr, "%s", prompt);
144     q = fgets(p, n, sys_stdin);
145     if (q == NULL) {
146         *p = '\0';
147         return p;
148     }
149     n = strlen(p);
150     if (n > 0 && p[n-1] != '\n')
151         p[n-1] = '\n';
152     return (char *)PyMem_REALLOC(p, n+1);
153 }
154 
155 /* No-nonsense fgets */
156 char *
Py_UniversalNewlineFgets(char * buf,int n,FILE * stream,PyObject * fobj)157 Py_UniversalNewlineFgets(char *buf, int n, FILE *stream, PyObject *fobj)
158 {
159     return fgets(buf, n, stream);
160 }
161 
162 
163 #include <stdarg.h>
164 
165 void
PySys_WriteStderr(const char * format,...)166 PySys_WriteStderr(const char *format, ...)
167 {
168     va_list va;
169 
170     va_start(va, format);
171     vfprintf(stderr, format, va);
172     va_end(va);
173 }
174